The report was criticized because it did not mention the recommendations of organizations like the American Medical Association or the American Psychological Association and interpreted some studies in ways that were at odds with experts in the field, like a Swedish study that found higher rates of poverty and suicide among transgender people.

“There is a deep chasm between established medical research and the underlying analysis your Department used to justify this policy, and we call on you to reverse your recommendations,” the House Democrats wrote.

The letter also asks the Department of Defense to “disclose the individuals on the Panel of Experts and the principal advisors they consulted in drafting the policy recommendations.”

The Democrats accuse the Department of Defense of “cherry-picking of outdated studies to support its conclusions.”

The letter also goes after the Department of Defense’s claim that transgender people are “undeployable” for a year if they start hormone replacement therapy, citing medical standards that say that they need to be monitored for a year.

“The DOD report fails to mention that the author of these standards, Dr. Wylie C. Hembree, sent an October 2015 letter to the Pentagon’s Transgender Repeal Working Group in which he explained, ‘There is no reason to designate individuals as non-deployable after the commencement of hormone replacement therapy,'” the Democrats’ letter explained.

Last, the letter addresses unit cohesion, which the Department of Defense said would be undermined if transgender people were allowed to openly serve in the military, saying “the evidence used to reach these conclusions is simply unpersuasive.”

The effort behind the letter was led by Representative Joe Kennedy (D-MA). The Pentagon has not responded to it.